I have been playing pokemon go for about a week now and the game worked perfectly all this time. But recently when I logged in, the game fails to detect any of the nearby gyms or pokestops. There are'nt any nearby pokemon shown in the box below as well.There are like 2 pokestops and 3 gyms in my area but the game is not detecting any of them for a couple of days now.
I find that when I open the game it will most the map first and then populate it with gyms and pokestops. I'm guessing you gave it time to load (could take several minutes with a weak connection), but I would double check your data and Wi-Fi connections. If either is weak, turn it off as it may be causing your game to slow down as it tries to use the service but cannot receive enough information.
If I load the game in Wi-Fi and walk out of range before the game has loaded, it will get stuck at a loading screen indefinitely and I will have to do a full close and restart.